Spindle counterbalance



P D. c. KL'AUSMEYER 1,729,583

SPINDLE COUNTER BALANCE Filed'OOt. 24,- 1924 2 Sheets-Sheet 1 a'ywmtoz Sept. 24, 1929- b. c. KLAUSME YER SPINDLE COUNTER BALANCE Filed Oct. 24, 1.924 2 Sheets-Sheet 2 anvwto'c Patented Sept. 24, 1929 I if i UNITED STATES PATENT OFFICE DAVID C. KLAUSMEYER, OF CINCINNATI, OHIO, ASSIGNOR TO THE CINCINNATI BICK- FORD TOOL COMPANY, OF OAKLEY, CINCINNATI, OHIO, A CORPORATION OF OHIO SPINDLE COUNTERBALANCE Application filed October 24, 1924. Serial No. 745,671.

This invention relates to drilling-machines balance. Another object of the invention is and it deals primarily with the means for to provide an auxiliary stop for the rotary counter-balancing the weight of the spindle element upon which the chain is wound and its associated elements whereby the whereby the parts may be brought to rest in spindle may readily be moved up and down a position in which the connection between 5 for the purpose of feeding the drill into and the counterbalance and the drill-spindle is out of the work; all while permitting the accessible through a suitable aperture formed spindle to rotate. in the drill-head whereby the spindle may be Here-tofore, it has been usual to employ disconnected from the counterbalance and a weight for the purpose of counterbalancreadily removed from the drill-head. A still no ing the spindle and it has, accordingly, further object of the invention is to provide been necessary to provide space in or adin a spring counterbalance simplified means jaceut the frame of the machine to accomfor regulating the tension of the spring and modate the movement of the weight. Furfor holding it under any desired degree of thermore, when a weight is employed it has tension. 65 to be of suitable proportions and means must Other objects and advantages will be in be provided for so that the path of the Weight part indicated in the fOllOWlIlg (lGSCllptlOD 111 t b i th i di t i it f the and in part rendered apparent therefrom in spindle; all of which has entailed some struc connection with the annexed drawings.

t bj ti Still f rth the employ- To enable others skilled in the art so fully t, f a i ht d t ak it ibl to apprehend the underlying features hereeasily to adjust the degree of the counterpull f that they may embody the same in the on th i dl t m t any particular eirc mvarious ways contemplated by this invention, stances f drawings depicting a preferred typical con- In an effort to overcome the various disstruction have been annexed as a part of this 7 advantages inherent in the weight type of disclosure and, in such drawings, like charcounterbalance and the inconveniences in the acters of reference denote corresponding installation, use and adjustment thereof parts throughout all the views, of which several spring counterbalance devices have 1 is an elevation of a portion of a heretofore been designed. These latter dedrill ng machmeembody ng the present m- 80 vices, which, in certain respects, have been a vention. Fig. 2 1s a hor1zontal section subdecided improvement over the weight type stantially on the line 22 of Fig. 3. Fig. 3

of counterbalance have, nevertheless, also is a View somewhat similar to Fig. 1 but havembodied certain structural objections which ing a portion of the casing broken away better h Prevented th f b i ti l to illustrate certain of the mechanism theresatisfactory and which this invention probeneath. A is a face view of the spring P9335 t Cure, housing with the cover thereof broken away This invention has for an object to probetter to show the means for holding the opvide an improved form of spring counterposite ends of the counterbalance spring.

balance for drilling machines which is ex- Fig. 5 1s a detail view of a fusee employed 1n ceedingly simple in construction; which may the counterbalancing device. Fig. 6 is a debe more readily assembled and dismantled tail side elevation of a portion of Fig. 1

than prior constructions and which permits showing particularly the means for attaching of ready removal of the normally inaccessible the spindle supporting chain with the spindle drill-spindle from the drill-head. A further and the means for moving the spindle vertiobject of the invention is to provide, in a cally in the head. Fig. 7 is a detail section spring type counterbalance, means to conthrough a port on ofthe spring housing and trol the spring and to prevent unnecessary the casing w thin which the housmg is mainunwinding thereof upon failure of the chain tained, showing certain stop-lugslater to be 50 connecting the spindle with the counterreferred to. Fig. 8 1s a view similar to Fig. 1 0

7 but showing the function of an auxiliary stop for the spring casing.

Referring more particularly to the drawings the invention is disclosed in its preferred form as embodied in a drill-head of which a portion is designated as 1. This head is of conventional form and is provided with the usual vertical hole 2 Within which is vertically shiftable a sleeve 3 forming a part of the drill-spindle unit. This sleeve does not rotate but it may be translated by means of a pinion l engaging with the teeth t of a rackbar 5 afiixed to one side of the sleeve. The

pinion 1 is carried by a shaft 6 journaled in the head and this shaft may be rotated by any suitable means to cause vertical movements of the sleeve Within the sleeve is rotatably journaled the usual drill-supporting spindle 7 which may be rotated by any suitable means common to drilling machines. The drillspi'ndle is maintained against endwise movement reiative to the sleeve and therefore partake-s of the vertical movements of the latter.

The weight of the sleeve 3, spindle 7 and their attached parts is sustained, without interfering with their vertical movements, by an improved form of spring counterbalance device maintained within a casing 8 carried by the drill-head 1. A link chain 9, having one end connected with the sleeve and the, opposite end connected wit-h the cou-nter-' balance affords convenient means for transmitting the weight of the former to the latter. The attachment of the chain to the sleeve may be effected by means of a block 10 secured by screw 10* to the rack-bar 5 and to which the chain is connected, as at 11. Itis to be noted that the teeth t of the rackbar terminate adjacent the lower end of the block 10 and therefore when the block is removed, as will later be described, rotation of the pinion 4 in one direction, will cause complete disengagement of rack and pinion and the sleeve and spindle may be withdrawn from the drill-head as a unit.

Tot-he casing 8 is secured, as by screws 12, a cover 13- formed with a bearing 14 for a short shaft 15 upon which is rotatably journaled. a housing 16. The shaft 15 is normally held against rotation in the bearing 14 by set screws-15 and 15 threaded through the walls of the bearing and which bear upon flattened surfaces 15 and 15 respectively formed on the shaft 15. The screws 15 and 15 preferablyengage the surfaces 15 and 15 above and below a horizontal plane passing through the axis of the shaft, better to receive and withstand the torsional strains to which the shaft is subjected. lVithin the housing 16 is helda spiral spring 17 of which one end issecured to the shaft 15 by a pin 18. The other end of the spring is formed as a hook 19- which engages the wall 20 of a slot 21 in the peripheral wall of the housing 16. The

housing 16 carries at its rear side a member 22 in the nature of a fusee on the periphery of which winds the chain 9. The periphery of the fuses provides a shallow groove 23 and this groove is of spiral formation so that it progressively increases in distance from the axis of rotation of the fusee. The chain is attached at one end to the fuses at a point most remote from its axis of rotation as by means of its connection with a block 24 held by a screw 25 in a slot 26 formed in the fusee.

It will be perceived that, in consequence of this arrangement, as the spindle is lowered, and as the spiral spring 17 increases in tension, the pointed which the chain, leaves the fusec will be more and more remote from the axis of rotation; in other words the leverage effect of the fusee on the spring increases as the tension of the spring increases, and conversely. In this manner the chain 9 is subjected to a constant tension in all positions of the spindle although the spiral spring has its tension increased as it becomes wound more and more tightly.

It sometimes happens in both spring and weight counterbalances that the cable or chain connecting the spindle with the counterbalance breaks under the strains to which it is subjected. In the spring type of counterbalance this breakage is immediately followed by rapid and complete unwinding of the counterbalance spring which not infrequently damages the spring or other parts of the counterbalance. Also unwinding of the spring caused the chain to be drawn into the casing; from which position it was difficult to be retrieved for subsequent attachment to the drill-spindle. An important feature of this invention consists in the provision of a safety device adapted, upon failure of the chain to support the spindle, to limit the unwinding action of the spring'and to bring the parts of the counterbalance to rest without injury thereto. This may conveniently be effectedby formingon the cover 13 an abutment in the nature of a. lug 27 located in the annular path of a similar abutment 28. carried by the rotatable housing 16'. For conveni'ence of manufacture the lug 28 may be formed integral with a cover-plate 29 fitted within an annular recess 30 in: the housing and held therein as by means of screws 31. The-lugs 27' and 28 are so arranged that during the normal operation of'the machine the housing 16 and the fuses carried thereby are permitted to receive almost a complete rotation before the surface 28 of the lug 28 contacts with the surface 27 of the lug 27 thereby stopping the downward movement ofthedrill-spindle. This extent of rotation of the parts permits the drill-spindle to be given vertical movements of sufficient amplitude to perform the drilling operations. Upon failure of the chain, which causes the spring 17 to be relieved of the weight of the spindle and its associated elements, the spring unwinds thereby rotating the housing 16 until the surface 28 of the lug 28 is brought into contact with the surface 27 b of the lug 27. This contact arrests the rotation of the parts and prevents unnecessary unwinding of the spring.

Upon failure of the spindle to be supported, unless some special means was provided the spindle would fall of its own weight clear of the drill-head which falling might readily injure the workman, the work or the spindle. This is prevented in the present. machine by locating the block 10 at the upper end of the rack-bar in which place it acts as a stop against the pinion 4 and prevents falling of the spindle.

It occasionally happens that it is necessary to remove the drill-spindle unit from the drill-head. In prior machines this has entailed quite some difiiculties first because the connection between spindle and the chain was usually more or less inaccessible and second it was necessary, both when disconnecting the spindle from the chain and also when renewing this connection, to overcome the pull of the counterbalance. In weight counterbalances this was sometimes effected by propping up the weight and in the spring counterbalance this could most conveniently be effected by completely unwinding the spring and thereby relieving it of all tension. These expedients were dangerous, bothersome and wholly unsatisfactory.

The present invention overcomes this difliculty in a very simple and ingenious manner now to be described. The casing, or prefer ably the cover 13 thereof carries a normally inetlective abutment adapted, at any desired time to be brought into the path of another abutment carried by the rotatable housing 16, thus by a suitable adjustment of one of the abutments the rotatable housing, the

- spring therein, and the fusee carried thereby may all be brought to rest thereby relieving the chain of the counterpull of the spring. One convenient means for effecting this result comprises a screw 32 threaded into the casing 13 and having an end 32 adapted to be brought into the path of the lug 28 whereby upon elevation of the spindle the lug will engage the screw and bring both the rotatable member and the spindle to rest in a predetermined position with the spring ineffective to exert a counterpull on the chain. The lug 28 and the screw 32 are so arranged that when they are in contact the screw 10 that secures the block 10 to the spindle is in view and readily accessible through an orifice 33 in the drillhead (see Fig. 3). It will be understood that with the parts in these positions the screw 10 may readily be taken out, thus disconnecting the block 10 from the rack-bar 5 and permitting the spindle to be dropped clear of the pinion 4 and the drillhead, without any movement of the parts of the counterbalance. Fig. 8 shows the screw 32 adjusted to its effective position and Fig. 7 shows it maintained out of the path of the lug 28 as by means of a spacer-nut 34, the same being provided to prevent accidental or unauthorized shifting of the screw into the path of the lug.

lVhen, for any reason, it is desired to change the tension of the spring 17 this may readily be done by applying a suitable wrench to the squared end 15 of the shaft 15, loosening the set-screws 15 and 15 and then, by means of the wrench, rotating the shaft until the desired tension is secured,after which the screws 15 and 15 may again be adjusted into contact with the flats 15 and 15 to hold the parts in their adjusted positions.

From the foregoing it will be perceived that I have provided an exceedingly simple, compact, inexpensive and efficient counterbalance embodying means for controlling the action of the counterbalance spring, means to permit of ready removal of the spindle from the drill-head, and means to provide for the necessary adjustment of the counterbalance spring.

lVithout further analysis, the foregoing will so fully reveal the gist of this invention that others can, by applying current knowledge, readily adaptv it for various utilizations by retaining one or more of the features that, from the standpoint of the prior art, fairly constitute essential characteristics of either the generic or specific aspects of this invention and, therefore, such adaptations should be, and are intended to be, comprehended within the meaning and range of equivalency of the following claims.

Having thus revealed this invention, I claim as new and desire to secure the following combinations and elements, or equivalents thereof, by Letters Patent of the United States l. A drilling machine combining a drillspindle, and a spring counterbalance therefor comprising a rotatable member; a flexible connection between said rotatable member and said drill-spindle for transmitting to the former the weight of the latter; a spring connected with said rotatable member and adapted to exert a counterpull on said flexible connection; and means to limit the rotation of said rotatable member whereby the spring cannot fully unwind upon being released from the weight of said drill spindle.

2. A drilling machine combining a drill spindle, and a spring counterbalance therefor comprising a rotatable member; a flexible connection between said rotatable member and said drill-spindle for transmitting to the former the weight of the latter; a spring connected with said rotatable member and adapted to exert a counterpull on said flexible conne'ction and means acting directly upon said rotatable member to limit its rotation to less than the range of said spring.

3. A drilling machine combining a drillspindle, and a spring counterbalance therefor comprising a rotatable member; a flexible connection between said rotatable member and said drill-spindle for transmitting to the former the weight of the latter; a spring connected with said rotatable member and adapted to exert a counterpull on said flexible connection; an abutment carried by said rotatable member; and means cooperating with said abutment to limit the rotation of said rotatable member.

' 4. A drilling machine combining a drillspindle, and a spring counterbalance therefor comprising a rotatable member; a flexible connection between said rotatable member and said drill-spindle for transmitting to the former the weight of the latter; a spring connected with said rotatable member and adapted to exert a counterpull on said flexible connection; and means operative upon failure of the flexible connection to limit the unwinding of the spring.

5 A drilling machine combining a drillspindle and a spring counterbalance therefor comprising a casing supported by the drillhead; a member rotatably mounted in said casing; a fusee carried by said rotatable member; a flexible connection between said fusee and the spindle; a spring having one end connected with said rotatable member and adapted to exert a counterpull on said flexible connection to support the weight of said spindle; and an abutment carried by said casing and maintained in the path of movement of a portion of said rotatable member to limit the rotary movement of said rotatable member.

6. A drilling machine combining a drillspindle, and a spring counterbalance therefor comprising a rotatable member; a flexible connection between said rotatable member and said drill-spindle for transmitting to the former the weight of the latter; a spring connected with said rotatable member and adapted to exert a counterpull on said flexible connection; and means located in the path of rotation of said rotatable member to limit its movement to less than a complete rotation.

7. A drilling machine combining a drillspindle and a spring counterbalance therefor comprising a rotatable member; a flexible connection between said rotatable member and the spindle; a spring operatively connected with said rotatable member; means to limit the rotation of said rotatable member; and an auxiliary means to arrest the rotation of said rotatable member intermediate its extreme positions of rotation.

'8. In a drilling machine, a drill-spindle and a counterbalance device for said drillspindle, said counterbalance comprising a casing; a shaft journaled in said casing; a

housing rotatably mounted in said casing; a spiral spring located in said housing and operatively connecting said housing and said shaft; a fusee carried by said housing; a flexible connector secured at its opposite ends to said spindle and to said fusee and adapted to be wound upon the latter; a lug carried by said rotatable housing; a lug carried by said casing in the path of movement of said first named lug to limit the rotary movements of said housing; and auxiliary means adapted to be placed in the path of move ment of said first named lug to arrest the rotation of the parts before said parts reach their normal stopping positions.

9.A drilling machinecombining a drillhead provided with an orifice; a spindle translatably mounted in said drill-head; a spring counterbalance for said spindle, said counterbalance including ai'otatable memher, a flexible connector adapted to be wound upon said rotatable member; means tovattach one end ofsaid flexible connector with said spindle; and means to arrest the rotation of said rotatable member with said chain attaching means adjacent said orifice to permit of detachment of said chain from said spindle. 10. In a drilling machine, a drill head provided with an orifice; a spindle translatably mounted in said drill-head; means to cause translation of said spindle in said drill-head; a counterbalance for said spindle, said counterbalance including a rotatable member, a flexible connector attached at one end to said spindle and adapted to be wound upon said rotatable member as said spindle is elevated; and means to're-nder said counterbalance ineifective to produce a counter-pull on said spindle when the spindle is in a predetermined position with respect to said orifice.

11. In a drilling machine, a drill-head provided with an orifice; as-pindle translatably mounted in said drill head; a rack bar carried by said spindle; a pinion rotatably journaled in said drill-head and meshing with said rack bar; a counterbalance device for said spindle; a flexible connector adapted to receive the counterpull of said counterbalance; means toattach one end of said connector with said spindle, said means including an attachment block located adjacent the'end of said rack-bar and forming an abut-ment to prevent disengagement of the rack and pinion; a screw securing said attachment block to said spindle; and a movable abutment adapted to bebrought into the path of movement of a portion of said counterbalance to render said counterbalance ineffective and said connector strain-free in a position wherein said screw is accessible through said orifice.

12.. A drilling machine combining a drillspindle and a counterbalance therefor, comprising a casing; a shaft rotatably journaled in said casing; a housing rotatably mounted on said shaft; a spiral spring within said housing and having one end connected with the housing and the other end secured to said shaft; a fusee secured to said housing; a flexible connector having one end secured to the fusee and the other end attached to said drill spindle; means for applying power to the shaft to change the tension of said spring; means carried by said casing and adapted to engage said shaft to hold it against rotary movement in its adjusted position; and an abutment carried by said rotatable housing, and two abutments carried by said casing one of which is adjustable, said abutments being adapted to bring said rotatable housing to rest in either of two positions.

13. A drilling machine combining a drillspindle and a counterbalance therefor comprising a casing; a shaft rotatably journaled in said casing; a housing rotatably mounted on said shaft; a spiral spring within said housing and having one end connected with the housing and the other end secured to said shaft; a fusee secured to said housing; a flexible connector having one end secured to the fusee and the other end attached to said drill spindle; means for applying power directly to the shaft to change the tension of said spring; and set screws threaded through said casing engaging flattened portions of the shaft at opposite sides thereof and at opposite sides of a plane passing through the axis of the shaft.

In witness whereof, I have hereunto subscribed my name.

DAVID C. KLAUSMEYER. 

